Biology Exam

Independent Variable

The variable being mainpulated

Dependent Variable

Result of experiment

Control Treatment

No manipulation

Experimental Treatment

New, unapproved drug being tested

Controlled Variables

Instructions consistent with each group

Hypothesis

A possible answer to the question being asked

Theory (how or why)

A well tested, proven explantion backed by massive amounts of evidence

Law (what)

Reliable description of a natural pattern in living things

Ex: Gravity

Homeostasis

Keeping internal conditions balanced

Asexual

Genetically identical

Reproduce alone

Sexual

Combine genetic identity

Reproduce with one another

Organic Molecules (living)

Carbon-based backbone

At least one C-H bond

Inorganic Molecules (non-living)

No carbon based backbone

C-H bonds

Macromolecules

• Carbohydrates

• Proteins

• Lipids

• Nucleic acids

Cell Theory

All living things are made up of cells, and new cells come from the division of a preexisting one

Prokaryotic

Small, lack organelles

DNA floats in cytoplasm

Circular DNA

Eukaryotic

large, many organelles

DNA in nucleus

Linear DNA

Theory of Endosymbiosis

Free living prokaryotic cells engulfed other prokaryotic cells billions of years ago, forming eukaryotic organelles such as the mitochondria and chlroplasts

DNA

A double helix alternating sugar and phosphate groups

Each side connects to small units called nucleotides

Base Pairs

Formed by pairs of nitrogen bases that connect the two strands with hydrogen bonds

Homologous Chromosomes

Pair of matching chromosomes

One from mom one from dad

Sister Chromosomes

Two identical halves

Genes

Basic units of heredity made of DNA that codes for a specific trait

Alleles

A specific variant or form of that gene

Genotype

The actual set of alleles an organism inherits or carries inside its genetic code

(BB or Bb)

Phenotype

Physical trait

Chromosomes

Large, organized packages made of tightly wound DNA

Located inside the cell nucleus

Dominant

An allele that is always expressed in the phenotype

Recessive

An allele that is hidden or masked by a dominant allele and is only expressed when two copies are present

Homozygous

Having two identical alleles

(AA or aa)

Heterozygous

Having two different alleles

(Aa)

Polygenic Inheritance

A single physical trait is controlled by two or more different genes

Ex: Skin color and height

Multifactorial Inheritance

Traits are influenced by both polygenic genetic factors and external environmental conditions

Ex: Risk of diabetes depends on both genes and nutrition

Codominance

Both alleles are active and fully expressed at the same time

Ex: Black fur mom and White fur dad: Cats with both colors

Incomplete Dominance

Neither allele is fully dominant over the other

Ex: Red flower and a White flower make a pink flower

Complete Dominance

One or the other

Brown eyes or blue eyes

Genetic Inheritance

Is the permanent DNA you inherit from mom and dad

Epigenetic Inheritance

The passing of chemical markers that turn genetics on or off

Evolution

The change in inherited traits over time

Fitness

an organism's ability to survive, find a mate, and reproduce, allowing it to pass its genes on to the next generation

Microevolution

a small-scale change in allele frequencies (gene versions) within a single population over a short period of time

lines of evidence that supports evolutionary theory

life changes over time and shares common ancestors

• Rock data (fossils)

• DNA

• Geography

• Observation

Generate science informed arguments against common misconceptions regarding evolution

It’s wrong to say evolution isn’t happening because of antibiotic resistance

Describe the steps of natural selection

• variation

• inheritance

• selection

• adaptation

Explain how sexual selection is a specific type of natural selection

focuses entirely on an organism’s reproduction success rather than general survival.

Ex: Peacock feathers

Natural Selection

certain traits help an organism survive and reproduce.

Genetic Drift

Randomly happens to a population

Describe the role of mutations in evolution

When a mutation occurs in an organisms gene, depending on if its better for the environment they may produce more organisms with that gene

Directional Selection

Occurs when a phenotype at one extreme is favored by the environment

Ex: Moths covered from the factory production

Stabilizing Selection

Occurs when a phenotype at each end of the spectrum are less suited to the environment then the ones in the middle

Ex: Lower weight or higher weight at birth doesn’t survive as well

Diversifying Selection

Occurs when the extremes of the phenotype range are better suited to the environment than individuals in the middle

Ex: Beak size

Speciation

When one species diverges into two

Allopatric

Populations become geographically seperated

Sympatric

Speciation in the same place at the same time

Ex: A few fruit flies went to a different type of apple and they ended up liking that one better, causing them to split into two groups (One likes new apple One likes old apple)

Discuss how transitional fossils support evolutionary theory

Rock dating allows you to look at the fossils to determine if bone structure has changed over time

How does anatomy and DNA support evolutionary theory.

showing that related species share physical traits and genetic codes inherited from common ancestors

Explain how the ancient movement of Earth’s land masses influences the distribution of species on Earth

continental drift

Bacteria

Cell type: Prokaryotic

Environment: Found almost everywhere

Archaea

Cell Type: Prokaryotic

Environment: Hot springs or deep in the seas

Eukarya

Cell type: Eukaryotic

Ex: Animals and Plants

Cohesion

Sticks to other surfaces

Adhesion

Sticks to itself

Eukaryotic Organelles

• Ribosomes

• “ER”

• Cytoplasm

• Golgi Apparatus

• Mitochondria

• Chlorplasts

Ribosomes

tiny cellular structures made of RNA and protein that build proteins for the cell